CN108306660B

CN108306660B - Wireless communication system

Info

Publication number: CN108306660B
Application number: CN201810025993.6A
Authority: CN
Inventors: 行正浩二; 江口正; 浅井一志
Original assignee: Canon Inc
Current assignee: Canon Inc
Priority date: 2017-01-11
Filing date: 2018-01-11
Publication date: 2022-06-24
Anticipated expiration: 2038-01-11
Also published as: US20180198490A1; JP7263568B2; JP2022040256A; US20190260423A1; CN115065387B; CN115065387A; US10326499B2; EP4358425A2; CN108306660A; US10560157B2; EP3930207B1; EP3349365A1; EP3930207A1; EP3349365B1

Abstract

The present invention relates to a wireless communication system including: a first communication device comprising a first antenna and a second antenna; a second communication device comprising a third antenna and a fourth antenna; a first communication control unit that controls wireless communication based on electric field coupling or magnetic field coupling between the first antenna and the third antenna; and a second communication control unit that controls wireless communication based on electric field coupling or magnetic field coupling between the second antenna and the fourth antenna.

Description

Wireless communication system

Technical Field

The present disclosure relates to a wireless communication system.

Background

In recent years, a near field wireless communication system that performs communication based on electromagnetic field coupling between a pair of antennas placed close to each other has been proposed. Japanese patent laid-open No. 2009-268022 discusses a method of transmitting an electric signal without modulating an electric signal based on a baseband method in wireless communication based on electromagnetic field coupling, thereby realizing high-speed and low-delay communication with a simple circuit configuration.

However, in recent years, the amount of data to be communicated is increasing, and further high-speed communication is demanded to be realized in a wireless communication system.

Disclosure of Invention

According to one aspect of the disclosure, a wireless communication system includes: a first communication device comprising a first antenna and a second antenna; a second communication device comprising a third antenna and a fourth antenna; a first communication control unit configured to control wireless communication based on electric field coupling or magnetic field coupling between the first antenna and the third antenna; and a second communication control unit configured to control wireless communication based on electric field coupling or magnetic field coupling between the second antenna and the fourth antenna. The first antenna, the second antenna, the third antenna and the fourth antenna are located at the following positions: so that the electrical signal transmitted from the first antenna and received by the second antenna is weaker in strength than the electrical signal transmitted from the first antenna and received by the third antenna.

Further features of the invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

Drawings

Fig. 1 is a block diagram showing a system configuration of a wireless communication system 100.

Fig. 2A and 2B show a configuration example of a coupler in the wireless communication system 100.

Fig. 3A, 3B, 3C, 3D, 3E, and 3F illustrate electrical signals communicated in the wireless communication system 100.

Fig. 4 shows a system configuration of a wireless communication system 400.

Fig. 5 is a block diagram showing a system configuration of a wireless communication system 500.

Fig. 6 is a block diagram showing a system configuration of a wireless communication system 600.

Fig. 7A, 7B, 7C, 7D, 7E, and 7F illustrate interference of electrical signals communicated in the wireless communication system 100.

Fig. 8A and 8B show a configuration example of the wireless communication system 100 for preventing or reducing interference of electric signals.

Fig. 9A, 9B, 9C, and 9D show configuration examples of the wireless communication system 100 for preventing or reducing interference of electric signals.

Fig. 10A and 10B show a configuration example of a wireless communication system 100 including couplers that are movable in parallel.

Fig. 11A, 11B, and 11C show configuration examples of a wireless communication system 100 including a coupler that is rotatably movable.

Fig. 12A, 12B, and 12C show examples of the structure of the coupler.

Fig. 13A, 13B, and 13C show configuration examples of the wireless communication system 100 using a shield conductor to prevent or reduce interference of electric signals.

Fig. 14A, 14B, and 14C show a configuration example of a wireless communication system 100 that uses a shield conductor having a slit to prevent or reduce interference of electric signals.

Fig. 15A and 15B show another configuration example of the wireless communication system 100 including the couplers that are movable in parallel.

Fig. 16A, 16B, and 16C show another configuration example of the wireless communication system 100 including the coupler that is rotatably movable.

Fig. 17A and 17B show another configuration example of the wireless communication system 100 including the coupler that is rotatably movable.

Fig. 18A and 18B show another configuration example of the wireless communication system 100 including the coupler that is rotatably movable.

Fig. 19A, 19B, and 19C show simulation results regarding interference of electric signals in the wireless communication system 100 including the coupler that is rotatably movable.

Fig. 20A, 20B, and 20C show simulation results regarding interference of electric signals in the wireless communication system 100 including the coupler that is rotatably movable in the case of using the shield conductor.

Fig. 21A, 21B, and 21C show simulation results regarding interference of electric signals in the wireless communication system 100 including the coupler that is rotatably movable in the case of using the shield conductor having the slit.

Detailed Description

< System Structure >

In the following description, exemplary embodiments will be described with reference to the accompanying drawings. Fig. 1 shows a system configuration of a wireless communication system 100 (hereinafter referred to as system 100) according to the present exemplary embodiment. The system 100 includes a communication device 101 and a communication device 102 that performs wireless communication with the communication device 101. The communication apparatus 101 includes a transmission circuit 103, a transmission coupler 104, a reception circuit 107, a reception coupler 108, and a control unit 111. Similarly, the communication apparatus 102 includes a receiving circuit 105, a receiving coupler 106, a transmitting circuit 109, a transmitting coupler 110, and a control unit 112. The communication device 101 and the communication device 102 may be first and second parts of a single device.

In the present exemplary embodiment, the system 100 includes a structure for supporting the communication device 101 and the communication device 102 to maintain a predetermined positional relationship between the communication device 101 and the communication device 102 (e.g., a positional relationship in which the distance between the couplers is kept substantially constant). More specifically, the communication device 101 is a pan head section (pan head) of a network camera, and the communication device 102 is an image pickup section of the network camera. In another example, communication device 101 is a hand of a robotic arm, and communication device 102 is an arm coupled with the hand. In yet another example, the communication device 101 is a print head portion of a printer, and the communication device 102 is a main body portion of the printer. How system 100 is applied is not limited to these examples.

The transmission coupler 104, the transmission coupler 110, the reception coupler 106, and the reception coupler 108 are each a plate conductor serving as an antenna. However, the shape of the coupler is not limited thereto. The transmitting coupler 104 functions as an antenna for implementing wireless communication based on electromagnetic field coupling with the receiving coupler 106, and the transmitting coupler 110 functions as an antenna for implementing wireless communication based on electromagnetic field coupling with the receiving coupler 108.

The electromagnetic field coupling according to the present exemplary embodiment includes both electric field coupling and magnetic field coupling. In other words, wireless communication between couplers may be implemented based on electric field coupling, may be implemented based on magnetic field coupling, or may be implemented based on electric field coupling and magnetic field coupling. In fig. 1, the communication apparatus 101 and the communication apparatus 102 each include two couplers for transmission and reception, but at least one or more of the communication apparatus 101 and the communication apparatus 102 may include three or more couplers.

The control unit 111 of the communication device 101 controls the transmission circuit 103 to perform processing for transmitting data to the communication device 102, and controls the reception circuit 107 to perform processing for receiving data from the communication device 102. Similarly, the control unit 112 of the communication apparatus 102 controls the transmission circuit 109 to perform processing for transmitting data to the communication apparatus 101, and controls the reception circuit 105 to perform processing for receiving data from the communication apparatus 101. The control unit 111 can control a functional unit (not shown) included in the communication apparatus 101 based on data received by the communication apparatus 101 by controlling the receiving circuit 107. Similarly, the control unit 112 can control a functional unit (not shown) included in the communication apparatus 102 based on data received by the communication apparatus 102 by controlling the reception circuit 105. Here, examples of the functional unit include a display control unit that causes an image based on the received data to be displayed on a display unit, and a transmission unit that transmits the received data to an external device.

The transmission circuit 103 generates an electric signal based on the control of the control unit 111, and transmits the electric signal from the transmission coupler 104 to the reception coupler 106 based on a baseband scheme that transmits the electric signal without modulating the electric signal. Similarly, the transmission circuit 109 generates an electric signal based on the control of the control unit 112, and transmits the electric signal from the transmission coupler 110 to the reception coupler 108 based on the baseband scheme. The receiving circuit 107 transmits the electric signal received by the receiving coupler 108 to the control unit 111. Similarly, the receiving circuit 105 transmits the electric signal received by the receiving coupler 106 to the control unit 112.

Fig. 2A and 2B show configuration examples of a transmitting coupler and a receiving coupler in the system 100. Fig. 2A is a perspective view of a portion of the system 100, and fig. 2B shows a portion of the system 100 viewed from a positive X-axis direction of a coordinate system 200 defined by X, Y, and Z axes that are orthogonal to each other. The transmitting coupler 104 and the receiving coupler 108 are mounted on the same surface of a plate-like member included in the communication device 101, and are located substantially on the same plane. The transmitting coupler 110 and the receiving coupler 106 are mounted on the same surface of a plate-like member included in the communication device 102, and are located substantially on the same plane.

The transmitting coupler 104 and the receiving coupler 106 are located close to each other and at positions facing each other in the Z-axis direction. In other words, the transmitting coupler 104 and the receiving coupler 106 at least partially overlap each other when viewed from the Z-axis direction. Similarly, the transmitting coupler 110 and the receiving coupler 108 are located close to each other and at positions facing each other in the Z-axis direction. In such a configuration, data transmission from the communication device 101 to the communication device 102 is realized by transmitting an electric signal from the transmitting coupler 104 to the receiving coupler 106 in the positive Z-axis direction. Data transmission from the communication device 102 to the communication device 101 is achieved by transmitting an electrical signal in the negative Z-axis direction from the transmit coupler 110 to the receive coupler 108.

In fig. 2A and 2B, each coupler is shown to include a long side substantially parallel to the X-axis direction, but the shape and mounting direction of each coupler are not limited thereto, and may be different shapes and different directions as long as the respective transmitting couplers and receiving couplers can establish electromagnetic field coupling therebetween. For example, the transmit coupler 110 and the receive coupler 108 may each have a long side substantially parallel to the Y-axis direction, and the transmit coupler 104 and the receive coupler 106 may each have a long side substantially parallel to the X-axis direction. Alternatively, the transmitting coupler 110 and the receiving coupler 106 may be linearly arranged in the X-axis direction, and the transmitting coupler 104 and the receiving coupler 108 may be linearly arranged in the X-axis direction. The shape of the coupler may be U-shaped, L-shaped, or other shapes.

Fig. 3A to 3F show examples of waveforms of electric signals transmitted and received when the communication device 101 and the communication device 102 carry out communication based on electric field coupling. The horizontal axis in each of fig. 3A to 3F represents time. First, a first transmission signal shown in fig. 3A generated by the transmission circuit 103 is input to the transmission coupler 104. The receiving coupler 106 is coupled with the transmitting coupler 104 by electric field coupling, thereby generating a first receiving signal shown in fig. 3B at the receiving coupler 106 based on inputting the first transmitting signal to the transmitting coupler 104. The receiving circuit 105 performs conversion processing on the first received signal to generate a first conversion completion signal shown in fig. 3C, which has a similar waveform to the first transmitted signal. The conversion processing performed by the receiving circuit 105 includes, for example, processing of converting a received analog signal into a digital signal by comparing the analog signal with a threshold value by a comparator. The transmission of the first electric signal from the communication apparatus 101 to the communication apparatus 102 is realized by the above-described processing.

The transmission of the second electric signal from the communication apparatus 102 to the communication apparatus 101 is also realized by the similar processing. More specifically, the second reception signal shown in fig. 3E is generated at the reception coupler 108 based on inputting the second transmission signal shown in fig. 3D generated by the transmission circuit 109 to the transmission coupler 110. Then, the receiving circuit 107 performs conversion processing on the second reception signal to generate a second conversion completion signal shown in fig. 3F, which has a similar waveform to the second transmission signal.

In this way, provision of the transmission coupler and the reception coupler to each of the communication device 101 and the communication device 102 enables bidirectional communication to be implemented between the communication device 101 and the communication device 102. The communication apparatus 101 can perform data transmission and data reception asynchronously using different couplers for each of the data transmission and the data reception, and thus can achieve high-speed communication as compared with, for example, performing transmission and reception alternately in a time-sharing manner using a single coupler.

In the above description, the present exemplary embodiment is described with reference to the system 100 in which the communication apparatus 101 and the communication apparatus 102 perform bidirectional communication with each other, but two or more pairs of couplers may be used for unidirectional communication. Fig. 4 shows a system configuration of a wireless communication system 400 (hereinafter referred to as system 400) that implements unidirectional communication between a communication device 401 and a communication device 402. The communication apparatus 401 includes a transmission circuit 103, a transmission coupler 104, a transmission circuit 109, a transmission coupler 110, and a control unit 111. The communication device 402 includes the receiving circuit 105, the receiving coupler 106, the receiving circuit 107, the receiving coupler 108, and the control unit 112. The details of the respective components of the communication apparatus 401 and the communication apparatus 402 are similar to those of fig. 1, which are identified by the same reference numerals. However, the control unit 111 does not necessarily perform data reception processing, and the control unit 112 does not necessarily perform data transmission processing.

In the system 400, electrical signals are transmitted from the transmit coupler 104 of the communication device 401 to the receive coupler 106 of the communication device 402. The electrical signal is transmitted from the transmit coupler 110 of the communication device 401 to the receive coupler 108 of the communication device 402. If communication apparatus 401 transmits different electrical signals from transmit coupler 104 and transmit coupler 110 at the same time, system 400 enables a larger amount of data to be transmitted per unit time than if the electrical signals were transmitted from a single transmit coupler, thereby successfully achieving higher speed communication.

If the communication device 401 transmits the same electrical signal from the transmission coupler 104 and the transmission coupler 110, the system 400 enables data to be transmitted to the communication device 402 using one of the transmission couplers even when data transmission using the other transmission coupler fails due to the influence of noise or the like. By this effect, the system 400 can reduce, for example, data retransmission processing to be performed according to a communication failure, as compared with transmitting an electric signal from a single transmission coupler, thereby realizing higher-speed communication.

In fig. 4, the communication apparatus 401 includes two couplers for transmission and the communication apparatus 402 includes two couplers for reception, but the communication apparatus 401 may include three or more couplers for transmission and the communication apparatus 402 may include three or more couplers for reception. Alternatively, the communication device 401 may include two or more couplers for transmission and one or more couplers for reception, and the communication device 402 may include one or more couplers for transmission and two or more couplers for reception.

In fig. 1 and 4, the present exemplary embodiment is described with reference to a system 100 and a system 400 that implement communication between two communication apparatuses, but communication may be implemented between three or more communication apparatuses. Fig. 5 shows a system configuration of a wireless communication system 500 (hereinafter referred to as system 500) that implements communication between three communication devices, i.e., a communication device 501, a communication device 502, and a communication device 503. The communication apparatus 501 includes a transmission circuit 103, a transmission coupler 104, and a control unit 111. The communication device 502 includes a receiving circuit 105, a receiving coupler 106, a transmitting circuit 109, a transmitting coupler 110, and a control unit 112. The communication device 503 includes the receiving circuit 107, the receiving coupler 108, and the control unit 113.

The details of the respective components of the communication device 501, the communication device 502, and the communication device 503 are similar to those of fig. 1, which are identified by the same reference numerals. The control unit 113 performs communication processing similar to the control unit 111 and the control unit 112. However, the control unit 111 does not necessarily perform data reception processing, and the control unit 113 does not necessarily perform data transmission processing. In the system 500, electrical signals are transmitted from the transmit coupler 104 of the communication device 501 to the receive coupler 106 of the communication device 502, and electrical signals are transmitted from the transmit coupler 110 of the communication device 502 to the receive coupler 108 of the communication device 503.

In fig. 1, 4, and 5, the present exemplary embodiment is described with reference to an example in which a coupler for transmission and a coupler for reception are used while distinguishing them from each other, but one coupler may be used for both transmission and reception. For example, the system 100 shown in fig. 1 may be configured such that the reception circuit 107 includes both a function as a circuit for reception and a function as a circuit for transmission, and the control unit 111 switches whether to cause the reception circuit 107 to function as a circuit for transmission or a circuit for reception. When the receiving circuit 107 is used as a circuit for transmission, an electric signal is transmitted from the receiving coupler 108 to the transmitting coupler 110.

In the case where such processing for switching transmission and reception is performed in the communication apparatus 101, in the communication apparatus 102, the transmission circuit 109 also includes both a function as a circuit for transmission and a function as a circuit for reception, and the control unit 112 also performs processing for switching transmission and reception. In other words, whether to transmit an electrical signal from the transmission coupler 110 to the reception coupler 108 or to transmit an electrical signal from the reception coupler 108 to the transmission coupler 110 is controlled by the control unit 111 and the control unit 112.

With such a configuration, the system 100 can control whether bidirectional communication or unidirectional communication is implemented between the communication device 101 and the communication device 102. For example, it is conceivable that a case where data that should be transmitted from the communication apparatus 102 to the communication apparatus 101 occurs less frequently than data that should be transmitted from the communication apparatus 101 to the communication apparatus 102 occurs. In this case, during the time period when there is data that should be transmitted from the communication device 102, the system 100 may implement bidirectional communication by transmitting data from the transmitting coupler 104 to the receiving coupler 106, and also transmitting data from the transmitting coupler 110 to the receiving coupler 108. During periods of time when there is no data that should be transmitted from the communication device 102, the system 100 may implement unidirectional communication by transmitting data from the transmit coupler 104 to the receive coupler 106, and also transmitting data from the receive coupler 108 to the transmit coupler 110. By operating in this manner, the system 100 can efficiently use the coupler according to the data that should be communicated, thereby achieving high-speed communication.

The present exemplary embodiment is described focusing on an example of implementing wireless communication with single-ended transmission, but the present exemplary embodiment is not limited thereto. Wireless communication may be implemented through differential transmission. For example, in the case of applying differential transmission to the system 100 shown in fig. 1, the system 100 is modified to a system 600 as shown in fig. 6 in which each of the transmission coupler 104, the reception coupler 106, the reception coupler 108, and the transmission coupler 110 is replaced with two couplers for transmitting signals whose phases are opposite to each other. In fig. 6, similar components to those of the system 100 shown in fig. 1 are identified by the same reference numerals.

In the system 600, the communication device 101 includes the transmission coupler 114 and the reception coupler 118, and the communication device 102 includes the reception coupler 116 and the transmission coupler 120, in addition to the configuration of the system 100. The transmission coupler 114 functions as an antenna that implements wireless communication based on electromagnetic field coupling with the reception coupler 116, and the transmission coupler 120 functions as an antenna that implements wireless communication based on electromagnetic field coupling with the reception coupler 118.

The transmission circuit 103 transmits a signal having a phase opposite to that of the electric signal transmitted from the transmission coupler 104 to the reception coupler 106 from the transmission coupler 114 to the reception coupler 116. The transmission circuit 109 transmits a signal having a phase opposite to that of the electric signal transmitted from the transmission coupler 110 to the reception coupler 108 from the transmission coupler 120 to the reception coupler 118. Then, the receiving circuit 105 transmits the potential difference between the electric signal received by the receiving coupler 106 and the electric signal received by the receiving coupler 116 to the control unit 112. Similarly, the receiving circuit 107 transmits the potential difference between the electric signal received by the receiving coupler 108 and the electric signal received by the receiving coupler 118 to the control unit 111.

The configuration similar to the system 600 enables the communication device 101 and the communication device 102 to implement wireless communication by differential transmission between the communication device 101 and the communication device 102. Using differential transmission achieves lower external noise impact of wireless communication than using single-ended transmission. In fig. 6, a system 600 is described with reference to an example of applying differential transmission to the system 100 shown in fig. 1. However, differential transmission may be similarly applied to the system 400 shown in fig. 4 and the system 500 shown in fig. 5. Differential transmission can be applied to a system including the above-described coupler for switching transmission and reception.

< prevention or reduction of interference >

In the description of the above-described drawings, in fig. 3A to 3F, waveforms are described with reference to examples of waveforms in the case where interference does not occur in electric signals transmitted and received between two pairs of couplers. Depending on, for example, the positional relationship between the respective couplers, interference may occur in the transmitted and received electrical signals. For example, it is assumed in fig. 2A and 2B that the transmission coupler 104 and the reception coupler 108 are at a short distance from each other in the Y-axis direction, and the reception coupler 106 and the transmission coupler 110 are at a short distance from each other in the Y-axis direction. In this case, the electrical signal transmitted from the transmitting coupler 104 may be accidentally received by the receiving coupler 108, and the electrical signal transmitted from the transmitting coupler 110 may be accidentally received by the receiving coupler 106.

Fig. 7A to 7F show examples of waveforms of electric signals transmitted and received between the communication device 101 and the communication device 102 of the system 100 in a case where interference occurs. The horizontal axis in each of fig. 7A to 7F represents time. First, the first transmission signal shown in fig. 7A generated by the transmission circuit 103 is input to the transmission coupler 104, and the second transmission signal shown in fig. 7D generated by the transmission circuit 109 is input to the transmission coupler 110. At this time, as shown in fig. 7B, the receiving coupler 106 unexpectedly receives the signal transmitted from the transmitting coupler 110 in addition to the signal transmitted from the transmitting coupler 104, and noise 701 is contained in the first received signal generated at the receiving coupler 106. When the first received signal is subjected to conversion processing by the receiving circuit 105, as shown in fig. 7C, a first conversion completion signal including noise 702 is generated. Similarly, as shown in fig. 7E, noise 703 is contained in the second reception signal generated at the reception coupler 108 due to the influence of the signal transmitted from the transmission coupler 104. Then, when the second received signal is subjected to conversion processing by the receiving circuit 107, as shown in fig. 7F, a second conversion completion signal containing noise 704 is generated.

In the following description, a configuration of the system 100 for preventing or reducing occurrence of noise due to interference of electrical signals as in the example shown in fig. 7A to 7F will be described. The configuration to be described below can be applied in a similar manner to the above-described configurations of the system 100 shown in fig. 1 and the

systems

400 and 600 shown in fig. 4 and 6, and the like.

A configuration example of the system 100 for preventing or reducing interference of electrical signals will be described with reference to fig. 8A and 8B. Fig. 8A is a perspective view of a portion of the system 100, and fig. 8B shows a portion of the system 100 viewed from the positive X-direction of the coordinate system 200. In fig. 8A and 8B, components similar to those of fig. 2A and 2B are identified by the same reference numerals.

In fig. 8A and 8B, the communication device 101 includes a ground 801 between the transmit coupler 104 and the receive coupler 108, and the communication device 102 includes a ground 802 between the receive coupler 106 and the transmit coupler 110 to prevent or reduce the above-described interference. Each of the ground 801 and the ground 802 is, for example, a conductor connected to a reference potential point. In fig. 8A and 8B, the ground 801 and the ground 802 have a shape longer than the coupler in length in the X-axis direction, but the shapes of the ground 801 and the ground 802 are not limited thereto.

The provision of ground 801 to communication device 101 attenuates electromagnetic field coupling between transmit coupler 104 and receive coupler 108, thereby helping to prevent or reduce the occurrence of noise in the electrical signals received by receive coupler 108. Similarly, the provision of the ground 802 to the communication device 102 attenuates electromagnetic field coupling between the transmit coupler 110 and the receive coupler 106, thereby helping to prevent or reduce the occurrence of noise in the electrical signals received by the receive coupler 106. System 100 may include only one or more of ground 801 and ground 802.

Alternatively, as another configuration example for preventing or reducing interference, the coupler may be disposed such that the distance between the transmitting coupler 104 and the receiving coupler 108 in the Y-axis direction matches or exceeds a predetermined distance between the receiving coupler 106 and the transmitting coupler 110 in the Y-axis direction. The predetermined distance is set according to, for example, the intensity of the transmission signal and/or the allowable intensity of noise.

Alternatively, as another configuration example for preventing or reducing interference, transmission and reception may be implemented in a time-sharing manner in communication between the communication apparatus 101 and the communication apparatus 102. More specifically, the control unit 111 and the control unit 112 may control the transmission circuit 103 and the transmission circuit 109, respectively, to prevent the electric signals from being simultaneously transmitted from the transmission coupler 104 to the reception coupler 106, and from the transmission coupler 110 to the reception coupler 108.

In the above description with reference to fig. 8A and 8B, it is assumed that the ground 801 and the ground 802 each connected to a reference potential point are used as conductors provided between the transmitting coupler and the receiving coupler. However, the conductor provided between the transmitting coupler and the receiving coupler is not limited thereto, and a conductor insulated from a so-called electrical ground of the transmitting circuit or the receiving circuit in terms of direct current or alternating current may be provided on at least one of a position between the transmitting coupler 104 and the receiving coupler 108 and a position between the transmitting coupler 110 and the receiving coupler 106.

Next, a system 100 including a coupler of a different length from that of fig. 2A and 2B will be described as another configuration example for preventing or reducing interference with reference to fig. 9A to 9D. Fig. 9A is a perspective view of a portion of the system 100, and fig. 9B shows the portion of the system 100 viewed from the positive X-direction of the coordinate system 200. Fig. 9C shows a portion of the system 100 viewed from the positive Z-axis direction, and fig. 9D shows a portion of the system 100 viewed from the negative Z-axis direction. In fig. 9A to 9D, similar components to those of fig. 2A and 2B are denoted by the same reference numerals. In fig. 9B to 9D, the receiving coupler 906 and the transmitting coupler 110 of the communication apparatus 102 are shown in white for illustrative purposes.

In the configurations shown in fig. 9A to 9D, the receiving

couplers

106 and 108 shown in fig. 2A and 2B are replaced with receiving

couplers

906 and 908 of shorter lengths in the X-axis direction. Here, as shown in fig. 9B, each coupler has a flat shape, and thus the area of a portion of the transmission coupler 110 facing the reception coupler 908 is larger than the area of a portion of the transmission coupler 110 facing the reception coupler 906. With this configuration, a weaker electromagnetic field coupling is established between the transmission coupler 110 and the reception coupler 906 than between the transmission coupler 110 and the reception coupler 106 shown in fig. 2A and 2B. Similarly, a weaker electromagnetic field coupling is established between the transmit coupler 104 and the receive coupler 908 than between the transmit coupler 104 and the receive coupler 108 shown in fig. 2A and 2B. As a result, the system 100 can prevent or reduce the occurrence of noise due to interference of electrical signals transmitted and received between the communication apparatus 101 and the communication apparatus 102.

< movement of coupler position >

In the above description, the present exemplary embodiment is described with reference to an example in which the positional relationship between the couplers is fixed, but the relative positions of the couplers may be variable. In the following description, a configuration of the system 100 that can move the relative position of the coupler while maintaining a state in which wireless communication is implemented will be described. The configuration to be described below can also be applied to the above-described configurations such as the system 400 shown in fig. 4 and the system 600 shown in fig. 6 in a similar manner.

A configuration example of the system 100 including the couplers movable in parallel will be described with reference to fig. 10A and 10B. In fig. 10A and 10B, the components similar to those of fig. 2A and 2B are identified by the same reference numerals. Unlike the configuration of fig. 2A and 2B, the transmitting coupler 104 and the receiving coupler 108 are mounted on sides opposite to each other of the surfaces of the plate-like members included in the communication device 101. The communication device 102 includes two plate-like members to vertically enclose the plate-like members included in the communication device 101, the transmitting coupler 1010 is mounted on one of the two plate-like members, and the receiving coupler 1006 is mounted on the other of the two plate-like members. In other words, the transmitting coupler 1010 and the receiving coupler 1006 are located on sides opposite to each other of the surface of the plate-like member included in the communication device 101.

With such a configuration, a weaker electromagnetic field coupling is established between the transmitting coupler 1010 and the receiving coupler 1006 than between the transmitting coupler 110 and the receiving coupler 106 shown in fig. 2A and 2B. A weaker electromagnetic field coupling is established between the transmitting coupler 104 and the receiving coupler 108 than in the case of fig. 2A and 2B. As a result, system 100 prevents or reduces interference between electrical signals transmitted from transmit coupler 1010 to receive coupler 108 and electrical signals transmitted from transmit coupler 104 to receive coupler 1006.

Interference of electric signals can also be prevented or reduced by providing a ground at a position between the transmitting coupler 104 and the receiving coupler 108 (for example, an inner layer of a plate-like member included in the communication device 101). In the case where interference can be prevented or reduced in this way, by, for example, mounting the transmitting coupler 104 and the receiving coupler 108 at respective positions on the back surface and the front surface of the plate-like member, respectively, the distance between the transmitting coupler 104 and the receiving coupler 108 in the Y-axis direction can be shortened. As a result, this configuration also enables the communication device 101 and the communication device 102 to be reduced in size in the Y-axis direction.

The length of the transmit coupler 1010 and the receive coupler 1006 shown in fig. 10A and 10B in the X-axis direction is shorter than that of the transmit coupler 110 and the receive coupler 106 shown in fig. 2A and 2B. Therefore, the length of the transmission coupler 1010 in the X-axis direction is shorter than that of the reception coupler 108, and the length of the reception coupler 1006 in the X-axis direction is shorter than that of the transmission coupler 104. This enables the communication device 102 to be reduced in size in the X-axis direction.

The communication device 102 is movable in the X-axis direction of the coordinate system 200 while keeping the transmission coupler 1010 and the reception coupler 108 facing each other and keeping the transmission coupler 104 and the reception coupler 1006 facing each other. The control of the movement of the communication apparatus 102 may be achieved by controlling a driving unit (not shown) included in the communication apparatus 102, for example, by the control unit 112. The control of this movement causes the position of the transmit coupler 1010 relative to the receive coupler 108 and the position of the transmit coupler 104 relative to the receive coupler 1006 to move in the X-axis direction.

The communication apparatus 101 may move in the X-axis direction instead of the communication apparatus 102, or both the communication apparatus 101 and the communication apparatus 102 may move. The direction in which the coupler moves is not limited to the X-axis direction, but may be other directions. Without being limited to the range in which the transmitting coupler and the receiving coupler are kept facing each other, the coupler may be moved within the range that enables communication based on electromagnetic field coupling between the transmitting coupler and the receiving coupler. In the system 100 described with reference to fig. 2A and 2B, fig. 8A and 8B, and fig. 9A, 9B, 9C, and 9D, at least one or more of the communication device 101 and the communication device 102 may move in the X-axis direction.

Next, a configuration example of the system 100 including the rotationally movable coupler will be described with reference to fig. 11A, 11B, and 11C. Fig. 11A is a perspective view of a portion of system 100. Fig. 11B shows a portion of the system 100 viewed from the positive Z-direction of the coordinate system 200. Fig. 11C shows a portion of the system 100 viewed from the negative Z-axis direction. In fig. 11A, 11B, and 11C, components similar to those of fig. 2A and 2B are identified by the same reference numerals.

The transmitting coupler 1104 and the receiving coupler 1108 are mounted on a cylindrical member included in the communication device 101, and the transmitting coupler 1110 and the receiving coupler 1106 are mounted on a cylindrical member included in the communication device 102. The cylindrical member included in the communication device 101 and the cylindrical member included in the communication device 102 include center axes that coincide with each other and diameters that are different from each other. The transmit coupler 1104 faces the receive coupler 1106, and the transmit coupler 1110 faces the receive coupler 1108. In other words, the receiving coupler 1108 and the transmitting coupler 1110 are approximately located on the circumferences of circles centered on the same point as each other and having different diameters from each other, respectively. The transmitting coupler 1104 and the receiving coupler 1106 are respectively located approximately on the circumferences of circles centered on the same point as each other and having different diameters from each other.

In this configuration, electrical signals are transmitted from the transmit coupler 1104 to the receive coupler 1106 based on electromagnetic field coupling, and electrical signals are transmitted from the transmit coupler 1110 to the receive coupler 1108 based on electromagnetic field coupling. The diameter of the cylinder along which the transmitting coupler 1104 is mounted and the diameter of the cylinder along which the receiving coupler 1108 is mounted may be different from each other. Similarly, the diameter of the cylinder along which the transmitting coupler 1110 is installed and the diameter of the cylinder along which the receiving coupler 1106 is installed may be different from each other.

The communication device 102 can rotatably move around the center axis (axis in the Z-axis direction) of the cylindrical member while keeping the transmitting coupler 1104 and the receiving coupler 1106 facing each other and the transmitting coupler 1110 and the receiving coupler 1108 facing each other. The control of the movement of the communication apparatus 102 can be realized, for example, by the control unit 112 controlling a drive unit (not shown) included in the communication apparatus 102. This control of movement enables the transmit coupler 1110 and the receive coupler 1106 to move rotationally. The communication device 101, instead of the communication device 102, is rotationally movable around the central axis of the cylindrical member, thereby rotationally moving the transmitting coupler 1104 and the receiving coupler 1108. Alternatively, both the communication device 101 and the communication device 102 may be rotationally movable.

As shown in fig. 11B and 11C, the receiving coupler 1106 and the receiving coupler 1108 each have an arc shape as viewed from a reference direction (Z-axis direction) substantially parallel to the center axis of the cylindrical member. From the perspective of the reference direction, the transmit coupler 1104 and the transmit coupler 1110 each have a substantially circular shape. The transmission coupler 1104 having a substantially circular shape enables the transmission coupler 1104 and the reception coupler 1106 to face each other regardless of the rotation angle with respect to the rotational movement of the reception coupler 1106. The receive coupler 1106 having an arc shape may attenuate electromagnetic field coupling between the transmit coupler 1110 and the receive coupler 1106, as compared to the receive coupler 1106 having a substantially circular shape. The same applies to the shape of the transmit coupler 1110 and the receive coupler 1108. As a result, the system 100 prevents or reduces interference between the electrical signal sent from the transmit coupler 1104 to the receive coupler 1106 and the electrical signal sent from the transmit coupler 1110 to the receive coupler 1108.

Interference may also be prevented or reduced by providing a ground at one or more of a location between the transmit coupler 1104 and the receive coupler 1108 of the communication device 101, and a location between the receive coupler 1106 and the transmit coupler 1110 of the communication device 102.

The shape of each coupler is not limited to the examples shown in fig. 11A, 11B, and 11C. For example, one or more of the transmit coupler 1104 and the transmit coupler 1110 may have an arc shape, and at least any one of the receive coupler 1106 and the receive coupler 1108 may have a substantially circular shape. Alternatively, both the transmit coupler 1104 and the receive coupler 1106 may have an arc shape. In this case, the moving coupler can be rotated only within a range such that the transmitting coupler 1104 and the receiving coupler 1106 face each other, or within a range such that communication based on electromagnetic field coupling can be implemented between the transmitting coupler 1104 and the receiving coupler 1106. The same is true in the case where both the transmit coupler 1110 and the receive coupler 1108 have an arc shape.

As a modification of the configuration shown in fig. 11A, 11B, and 11C, the system 100 may be configured to round the configuration shown in fig. 10A and 10B around the Y-axis direction. More specifically, the configuration shown in fig. 11A, 11B, and 11C may be configured in the following manner. The receiving coupler 108 and the transmitting coupler 104 are mounted on the inner surface and the outer surface, respectively, of a cylindrical member included in the communication device 101. The communication device 102 sandwiches the cylindrical member in such a manner that the transmitting coupler 1010 mounted on the communication device 102 is located inside the cylindrical member and the receiving coupler 1006 mounted on the communication device 102 is located outside the cylindrical member. Similarly, the transmitting coupler 104 and the receiving coupler 108 may be mounted on the inner surface and the outer surface, respectively, of a cylindrical member included in the communication device 101. In such a configuration, one or more of the communication device 101 and the communication device 102 may be rotationally moved about the Y-axis direction.

In this modification, by providing a ground between the transmitting coupler 104 and the receiving coupler 108 (such as an inner layer of a cylindrical member included in the communication device 101), interference of electric signals can be prevented or reduced. In the case where interference can be prevented or reduced in this way, the distance between the transmitting coupler 104 and the receiving coupler 108 in the Y-axis direction can be shortened by, for example, mounting the transmitting coupler 104 and the receiving coupler 108 at respective positions on the inner surface and the outer surface of the cylindrical member, respectively. As a result, this configuration enables the communication device 101 and the communication device 102 to be reduced in size in the Y-axis direction.

< concrete construction example of coupler >

Fig. 12A, 12B, and 12C show specific configuration examples of the coupler in the wireless communication system 600 to which differential transmission is applied described above with reference to fig. 6. Fig. 12A, 12B, and 12C show specific configuration examples of a coupler in the case where wireless communication is realized by electric field coupling, magnetic field coupling, and electric field and magnetic field coupling, respectively. Hereinafter, the couplers shown in fig. 12A, 12B, and 12C will be referred to as a coupler for electric field coupling, a coupler for magnetic field coupling, and a coupler for electromagnetic field coupling, respectively.

In the electric field coupling coupler shown in fig. 12A, the transmission coupler formed of two conductors (the transmission coupler 104 and the transmission coupler 114) is electrically opened at one end opposite to the power supply point (P1) connected to the transmission circuit 103. Similarly, the receiving coupler formed by the two conductors (the receiving coupler 106 and the receiving coupler 116) is electrically opened at the end opposite to the power supply point (P2) connected to the receiving circuit 105. In the magnetic field coupling coupler shown in fig. 12B, the ends of the transmitting coupler and the receiving coupler opposite to the power feeding points (P1 and P2) are electrically short-circuited by the conductor 1200 and the conductor 1201, respectively. In the electromagnetic field coupling coupler shown in fig. 12C, a resistor 1202 having a characteristic impedance substantially matching the characteristic impedance of the transmission line connected between the transmission circuit 103 and the transmission coupler is inserted at one end of the transmission coupler opposite to the feeding point (P1). Similarly, a resistor 1203 whose characteristic impedance substantially matches that of the transmission line connected between the reception circuit 105 and the reception coupler is inserted at the end of the reception coupler opposite to the power supply point (P2).

The shape of the coupler based on various modes shown in fig. 12A to 12C is merely an example, and is not limited thereto as long as the coupler has the above-described characteristics. The wireless communication using the coupler configured as shown in fig. 12A, 12B, and 12C is not limited to differential transmission, and the wireless communication by single-ended transmission may be implemented using the coupler configured as shown in fig. 12A, 12B, and 12C.

< prevention or reduction of interference by Shield insertion >

The configuration of the system 100 for preventing or reducing interference of electrical signals is described above with reference to fig. 8A and 8B and fig. 9A, 9B, 9C, and 9D, and in the following description, another configuration of the system 100 for preventing or reducing interference will be described with reference to fig. 13A, 13B, and 13C. Fig. 13A is a perspective view of a portion of the system 100, and fig. 13B shows a portion of the system 100 viewed from the positive X-direction of the coordinate system 200. Fig. 13C shows a portion of the system 100 viewed from the positive Z-direction of the coordinate system 200. In fig. 13C, the configuration on the communication device 101 side is omitted, and only the configuration on the communication device 102 side is shown.

In the configuration shown in fig. 13A, 13B, and 13C, the communication device 101 includes a plate-shaped shield conductor 1300. The shield conductor 1300 is disposed so as to overlap the transmission coupler 104 and the reception coupler 108 when viewed from the Z-axis positive direction, and is also disposed on the side of the transmission coupler 104 and the reception coupler 108 opposite to the transmission coupler 110 and the reception coupler 106. In other words, the shield conductor 1300 is disposed so as to cover the transmission coupler 104 and the reception coupler 108 when viewed from the Z-axis negative direction. Similarly, the communication device 102 includes a shield conductor 1301, and the shield conductor 1301 is disposed so as to cover the transmission coupler 110 and the reception coupler 106 when viewed from the Z-axis positive direction.

By disposing the shield conductor close to the coupler in the above-described manner, interference of the electric signals generated between the transmission coupler 104 and the reception coupler 108 as in the example described with reference to fig. 7A to 7F can be prevented or reduced. The

shield conductors

1300 and 1301 may be any member as long as it is a conductor, and may be made of, for example, aluminum, copper, or the like. In the case of using a substrate pattern such as flame retardant type 4(FR4), the

shield conductors

1300 and 1301 may each be formed using a conductor layer of a surface layer or an inner layer different from a layer forming the coupler. The

shield conductors

1300 and 1301 may be connected to an electrical ground of the transmission circuit or the reception circuit in terms of direct current or insulated from the electrical ground of the transmission circuit or the reception circuit in terms of direct current/alternating current. The shield conductor may be provided only on any one of the communication device 101 and the communication device 102. The

shield conductors

1300 and 1301 do not necessarily completely cover the transmission coupler and the reception coupler when viewed from the Z-axis direction, and may be configured in a different manner as long as at least a part of the transmission coupler or the reception coupler and the shield conductor overlap each other.

By using a shield conductor including a slit, interference of electrical signals between couplers can be prevented or reduced. This configuration will be described with reference to fig. 14A, 14B, and 14C. Fig. 14A is a perspective view of a portion of the system 100, and fig. 14B shows a portion of the system 100 viewed from the positive X-direction of the coordinate system 200. Fig. 14C shows a portion of the system 100 viewed from the positive Z-direction of the coordinate system 200. In fig. 14C, the configuration on the communication device 101 side is omitted, and only the configuration on the communication device 102 side is shown.

In the configurations shown in fig. 14A, 14B, and 14C, the communication device 101 and the communication device 102 include a shield conductor 1400 inserted with a slit and a shield conductor 1401 inserted with a slit, respectively. The slit included in the shield conductor 1400 is located between the transmission coupler 104 and the reception coupler 108 when viewed from the Z-axis direction. Similarly, a slit included in the shield conductor 1401 is located between the transmission coupler 110 and the reception coupler 106 when viewed from the Z-axis direction.

By disposing the shield conductor 1400 including the slit close to the coupler in the above-described manner, interference of electrical signals due to coupling between the transmitting coupler 104 and the receiving coupler 108 can be prevented or reduced via the shield conductor 1400. The method for preventing or reducing interference of electric signals between couplers described with reference to fig. 13A, 13B, and 13C and fig. 14A, 14B, and 14C is particularly effective in the case of using a coupler for electric field coupling.

< sliding of coupler >

A configuration example of the system 100 including the parallel-movable couplers is described above with reference to fig. 10A and 10B, and an example in the case where the couplers configured in a different manner from that of fig. 10A and 10B are applied to the parallel-movable system 100 will be described with reference to fig. 15A and 15B. Fig. 15A is a perspective view of a portion of the system 100, and fig. 15B shows a portion of the system 100 viewed from the positive X-direction of the coordinate system 200.

In the configuration shown in fig. 15A and 15B, the transmitting coupler 104 and the receiving coupler 108 included in the communication device 101 are approximately equal in length and are arranged side by side in the Y-axis direction. The length of the transmission coupler 104 and the reception coupler 108 in the X-axis direction is shorter than the transmission coupler 1510 and the reception coupler 1506 included in the communication device 102. The communication device 101 can move in the X-axis direction within a range in which the transmission coupler 104 and the reception coupler 1506 overlap each other and the transmission coupler 1510 and the reception coupler 108 overlap each other when viewed from the Z-axis positive direction, that is, a range in which the communication device 101 and the communication device 102 can efficiently carry out communication. Communication device 102 may be moved within a similar range instead of communication device 101, or both communication device 101 and communication device 102 may be moved.

In the configuration example shown in fig. 15A and 15B, for the purpose of preventing or reducing interference of electrical signals between couplers, as described with reference to fig. 8A and 8B, a ground conductor may be provided between the transmission coupler 104 and the reception coupler 108 and/or between the transmission coupler 1510 and the reception coupler 1506. Alternatively, in the configuration example shown in fig. 15A and 15B, for the purpose of preventing or reducing interference of electric signals between couplers, a shield conductor may be provided as described with reference to fig. 13A, 13B, and 13C and fig. 14A, 14B, and 14C.

In the configuration examples shown in fig. 9A, 9B, 9C, and 9D, and 10A and 10B, for the purpose of preventing or reducing interference of electrical signals between couplers, configurations such as the above-described grounding and shielding for preventing or reducing interference may be applied. The various methods described above for preventing or reducing interference may be used in combination in a single system.

< System of rotatable movement (three-dimensional type) >

In the above description made with reference to fig. 11A, 11B, and 11C, focusing on an example in which the transmitting coupler and the receiving coupler have different lengths from each other, the configuration in which the couplers are made to be rotationally movable by being provided on the cylindrical member is described, but is not limited thereto. For example, in the case where the transmitting coupler and the receiving coupler are disposed apart from each other by a distance long enough not to cause a problem regarding interference of electric signals between the transmitting coupler and the receiving coupler disposed on one of the

communication devices

101 and 102, the transmitting coupler and the receiving coupler may have lengths equal to each other, as shown in fig. 16A, 16B, and 16C. In the configuration shown in fig. 16A, 16B, and 16C, the communication device 101 includes a transmitting coupler 1604 and a receiving coupler 1608, and the communication device 102 includes a transmitting coupler 1610 and a receiving coupler 1606. The transmit coupler 1604 is in communication with the receive coupler 1606, and the transmit coupler 1610 is in communication with the receive coupler 1608. Such a configuration also enables communication to be carried out while at least one of the communication device 101 and the communication device 102 is rotatably movable about the Z axis, similar to the configuration described above with reference to fig. 11A, 11B, and 11C.

In the configuration examples shown in fig. 16A, 16B, and 16C, for the purpose of preventing or reducing interference of electrical signals between the couplers, a ground conductor may be provided between the transmission coupler 1604 and the reception coupler 1608 and/or between the reception coupler 1606 and the transmission coupler 1610 as described with reference to fig. 8A and 8B. Alternatively, for the purpose of preventing or reducing interference of electric signals between couplers, in the configuration examples shown in fig. 16A, 16B, and 16C, a shield conductor may be provided as described with reference to fig. 13A, 13B, and 13C and fig. 14A, 14B, and 14C.

In the configurations shown in fig. 16A, 16B, and 16C, it is assumed that the transmitting coupler and the receiving coupler are provided on the same surface of the cylindrical member in each of the communication device 101 and the communication device 102. However, for the purpose of preventing or reducing interference of electrical signals between the couplers, the positions of the transmitting coupler and the receiving coupler are not limited thereto, and the transmitting coupler and the receiving coupler may be provided on different surfaces of the cylindrical member (as shown in fig. 17A and 17B). In the configuration shown in fig. 17A and 17B, the communication device 101 includes a cylindrical member a and a cylindrical member B, and the communication device 102 includes a cylindrical member C. A cylindrical member C is provided inside the cylindrical member a, and a cylindrical member B is further provided inside the cylindrical member C. A transmitting coupler 1704 included in the communication device 101 is provided on the inner surface of the cylindrical member a, and performs communication with a receiving coupler 1706 included in the communication device 102 provided on the outer surface of the cylindrical member C. The transmitting coupler 1710 included in the communication device 102 is provided on the inner surface of the cylindrical member C, and performs communication with the receiving coupler 1708 included in the communication device 101 provided on the outer surface of the cylindrical member B.

Similar to the configuration described with reference to fig. 11A, 11B, and 11C and fig. 16A, 16B, and 16C, such a configuration also enables communication to be carried out while at least one of the communication device 101 and the communication device 102 is rotationally moved about the Z axis. In this case, each cylindrical member is supported by a structure that does not interfere with the rotational movement, so that the positional relationship thereof is not largely changed.

In order to prevent or reduce interference of an electrical signal between the receiving coupler 1706 and the transmitting coupler 1710 included in the communication device 102, a cylindrical shield conductor may be provided inside the cylindrical member C so as to be sandwiched between the receiving coupler 1706 and the transmitting coupler 1710. The shield conductor may be connected to an electrical ground of the transmission circuit or the reception circuit in terms of direct current, or may be configured to be insulated from the electrical ground of the transmission circuit or the reception circuit in terms of direct current/alternating current. In the configuration examples shown in fig. 11A, 11B and 11C, fig. 16A, 16B and 16C, and fig. 17A and 17B, various configurations for preventing or reducing interference of electric signals between couplers may be used in combination.

< System of rotatable movement (planar type) >

Another configuration example in which the coupler is rotatably movable will be described with reference to fig. 18A and 18B. Fig. 18A is a perspective view of a portion of the system 100, and fig. 18B shows a portion of the system 100 viewed from the positive X-direction of the coordinate system 200. In the configuration example shown in fig. 18A and 18B, the communication device 101 includes a disc-shaped member, and the transmitting coupler 1804 and the receiving coupler 1808 are disposed substantially concentrically around the point 1900. The communication device 102 also comprises a disk-like member, and the transmit coupler 1810 and the receive coupler 1806 are also disposed substantially concentrically about the point 1901. The

points

1900 and 1901 are points overlapping each other when viewed from the positive Z-axis direction of the coordinate system 200. Communication is effected between the transmit coupler 1804 and the receive coupler 1806, and between the transmit coupler 1810 and the receive coupler 1808. Employing such a configuration enables communication to be carried out between the communication device 101 and the communication device 102 while one or more of the disc-shaped member included in the communication device 101 and the disc-shaped member included in the communication device 102 rotationally moves about an axis in the Z-axis direction passing through the point 1900 and the point 1901.

In the configuration example shown in fig. 18A and 18B, for the purpose of preventing or reducing interference of electrical signals between couplers, a ground conductor may be provided between the transmission coupler 1804 and the reception coupler 1808 and/or between the transmission coupler 1810 and the reception coupler 1806, as described with reference to fig. 8A and 8B. Alternatively, in the configuration example shown in fig. 18A and 18B, for the purpose of preventing or reducing interference of electric signals between couplers, as described with reference to fig. 13A, 13B, and 13C and fig. 14A, 14B, and 14C, the communication device 101 and/or the communication device 102 may be provided with a shield conductor.

In the configuration example shown in fig. 18A and 18B, for the purpose of preventing or reducing interference of electric signals between couplers, as described with reference to fig. 9A, 9B, 9C, and 9D, the system 100 may be configured such that it is assumed that a transmitting coupler and a receiving coupler, which communicate with each other, have different lengths from each other. For example, even in the case where the transmitting coupler 1810 is shortened and shaped into an arc shape, the receiving coupler 1808 having a circular shape enables communication to be conducted between the transmitting coupler 1810 and the receiving coupler 1808 even when the coupler is rotationally moved about the Z axis. Conversely, the transmitting coupler 1810 and the receiving coupler 1808 may have a circular shape and an arc shape, respectively. The transmitting coupler 1804 and the receiving coupler 1806 may have different lengths from each other. In the configuration examples shown in fig. 18A and 18B, a plurality of configurations for preventing or reducing interference of electric signals between couplers may be used in combination.

< effect of preventing or reducing interference of shield conductor >

The effect of preventing or reducing interference by the shield conductor described with reference to fig. 13A, 13B, and 13C and fig. 14A, 14B, and 14C will be described with reference to fig. 19A, 19B, and 19C to 21A, 21B, and 21C. Fig. 19A, 19B and 19C to fig. 21A, 21B and 21C show models and results of simulations in the case of using the rotatably movable coupler structure described with reference to fig. 18A and 18B. Fig. 19A, 20A, and 21A are perspective views of a model regarding the coupler section of the communication device 101, and fig. 19B, 20B, and 21B show the model when the coupler section of the communication device 101 is viewed from the Z-axis positive direction. These models are made assuming that the coupler is constructed by a coupler for electric field coupling that implements wireless communication by differential transmission, and that the conductor 2000 and the conductor 2001 form a transmitting coupler 1804, and the conductor 2002 and the conductor 2003 form a receiving coupler 1808. The transmit coupler 1804 includes a supply point P20 and the receive coupler 1808 includes a supply point P21.

In each model of the simulation shown in fig. 19A, 19B, and 19C to 21A, 21B, and 21C, the transmitting coupler 1804 and the receiving coupler 1808 are formed in a pattern on one surface (front surface) of a circular substrate included in the communication device 101. In the simulated model shown in fig. 20A, 20B, and 20C, the shield conductor 2100 is formed in a pattern on the other surface (back surface) of the circular substrate. In the simulated model shown in fig. 21A, 21B, and 21C, the shield conductor 2200 including the slit is formed in a pattern on the other surface (back surface) of the circular substrate. The coupler section of the communication device 102, which is arranged to face the coupler section of the communication device 101, is also constructed in a similar manner.

In the present simulation, the outer diameter of the circular substrate was 95mm, and the inner diameter was 56 mm. The outermost diameter of the coupler (the diameter of conductor 2003) is 79mm and the innermost diameter of the coupler (the diameter of conductor 2000) is 59 mm. The width of each of conductor 2000 and conductor 2001 is 1.5mm, and the width of each of conductor 2002 and conductor 2003 is 1.0 mm. The interval between the conductor 2000 and the conductor 2001 and the interval between the conductor 2002 and the conductor 2003 are each 1.5mm, and the interval between the conductor 2001 and the conductor 2002 is 2.0 mm. The outermost diameter and the innermost diameter of each of the shield conductor 2100 and the shield conductor 2200 are 80mm and 57mm, respectively. The width and diameter of the slit of the shield conductor 2200 are 0.5mm and 69mm, respectively. The interval between the circular substrate included in the communication device 101 and the circular substrate included in the communication device 102 was 0.5 mm.

Fig. 19C, 20C, and 21C are graphs each showing a result of simulation with respect to transmission characteristics between couplers facing each other in a case where the coupler section of the communication apparatus 101 and the coupler section of the communication apparatus 102 are arranged to face each other close to each other. The vertical axis and the horizontal axis of the graph represent the gain and the frequency, respectively, of the transmitted electrical signal. Solid and dashed lines in the figure represent the transmission characteristics between the transmit coupler 1804 and the receive coupler 1806, and between the transmit coupler 1804 and the receive coupler 1808, respectively. The graph indicates that the degree of preventing or reducing interference of electrical signals between couplers is large if the gain of the transmission characteristic between the couplers adjacent to each other indicated by the dotted line is small (if the difference between the gains is large) compared to the gain of the transmission characteristic between the couplers facing each other indicated by the solid line.

Fig. 19A, 19B, and 19C show models and results of simulations in the case where no shield conductor is provided. When the frequency of the electric signal is 100MHz, the transmission characteristic between the couplers facing each other (solid line) is-12.6 dB, and the transmission characteristic between the couplers adjacent to each other (dotted line) is-33.4 dB, thus generating a difference of 20.8dB between them.

Fig. 20A, 20B, and 20C show models and results of simulations in the case where the shield conductor 2100 is disposed to overlap with the coupler. When the frequency of the electric signal is 100MHz, the transmission characteristic between the couplers facing each other is-15.3 dB, and the transmission characteristic between the couplers adjacent to each other is-46.5 dB, thus generating a difference of 31.2dB between them. In other words, the simulation shows that as a result, an effect of reducing interference by 10.4dB can be obtained as compared with the configuration of the case where no shield conductor is used (the case of fig. 19A, 19B, and 19C).

Fig. 21A, 21B, and 21C show results and a model of a simulation in a case where the shield conductor 2200 including the slit is disposed to overlap with the coupler. When the frequency of the electric signal is 100MHz, the transmission characteristic between the couplers facing each other is-15.3 dB, and the transmission characteristic between the couplers adjacent to each other is-49.0 dB, so that a difference of 33.7dB is generated therebetween. In other words, the simulation shows that as a result, an effect of further reducing the interference by 2.5dB can be obtained as compared with the configuration of the case where the shield conductor 2100 without the slit is used (the case of fig. 20A, 20B, 20C).

As described above, the wireless communication system (system 100, system 400, system 500, and system 600) according to the present exemplary embodiment includes the first antenna and the second antenna. The wireless communication system includes a third antenna that performs wireless communication based on electromagnetic field coupling with the first antenna and a fourth antenna that performs wireless communication based on electromagnetic field coupling with the second antenna. With such a configuration, high-speed communication can be realized in a wireless communication system that implements communication based on electromagnetic field coupling. Each antenna is configured using the various methods for preventing or reducing interference described above such that the electrical signal transmitted from the first antenna and received by the second antenna has a strength weaker than that of the electrical signal transmitted from the first antenna and received by the third antenna. In other words, the wireless communication system can prevent or reduce interference of electrical signals between the first antenna and the second antenna and interference of electrical signals between the third antenna and the fourth antenna.

In the present exemplary embodiment, the wireless communication system is described based on an example of transmitting and receiving an electrical signal based on a baseband manner between a transmitting coupler and a receiving coupler. Based on the baseband method, the electric signal does not have to be modulated and demodulated, and thus the circuit scale can be reduced. However, the communication manner is not limited to this, and carrier communication may be implemented by modulating a carrier wave transmitted from the transmitting coupler to the receiving coupler based on an electric signal generated by the transmitting circuit, for example. In the case of carrying out carrier communication, interference of communication can be prevented or reduced by using different frequencies as the frequency of a carrier transmitted between one pair of transmission couplers and reception couplers and the frequency of a carrier transmitted between the other pair of transmission couplers and reception couplers.

According to the above-described exemplary embodiments, high-speed communication can be realized in a wireless communication system.

Although exemplary embodiments are described, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A wireless communication system, the wireless communication system comprising:

a first communication device comprising a first antenna and a second antenna;

a second communication device comprising a third antenna and a fourth antenna;

a movement control unit configured to move at least one of the first communication device and the second communication device relative to each other while maintaining a state in which a strength of an electromagnetic signal transmitted from the first antenna to the second antenna is weaker than a strength of an electromagnetic signal transmitted from the first antenna to the third antenna;

a first communication control unit configured to control wireless communication based on electromagnetic field coupling between the first antenna and the third antenna when the movement control unit moves at least one of the first communication device and the second communication device relative to each other; and

a second communication control unit configured to control wireless communication based on electromagnetic field coupling between the second antenna and the fourth antenna when the movement control unit moves at least one of the first communication device and the second communication device relative to each other,

wherein the first antenna is longer than the third antenna in a predetermined direction,

wherein the movement control unit moves at least one of the first communication device and the second communication device in a predetermined direction with respect to each other.

2. The wireless communication system according to claim 1,

wherein an area of a portion of the first antenna facing the third antenna is larger than an area of a portion of the first antenna facing the second antenna.

3. The wireless communication system according to claim 2,

wherein the first antenna and the second antenna are located on a surface of the first plate-like member, and

wherein the third antenna and the fourth antenna are located on a surface of the second plate-like member facing the first plate-like member.

4. The wireless communication system according to claim 3,

wherein the movement control unit moves one or more of the first plate-like member and the second plate-like member in a predetermined movement direction parallel to a surface of the first plate-like member and a surface of the second plate-like member, and

wherein the length of the second antenna in the predetermined moving direction is shorter than the length of the first antenna.

5. The wireless communication system according to claim 3,

wherein the movement control unit rotationally moves one or more of the first plate-like member and the second plate-like member about a predetermined axis perpendicular to a surface of the first plate-like member and a surface of the second plate-like member,

wherein the first antenna has a ring shape centered on the predetermined axis, and

wherein the second antenna and the third antenna each have an arc shape as viewed from the direction of the predetermined axis.

6. The wireless communication system according to claim 2,

wherein the movement control unit rotationally moves at least one of a first cylindrical member and a second cylindrical member around a predetermined axis serving as a central axis of the first cylindrical member, the first cylindrical member extending around the predetermined axis, the central axis of the second cylindrical member coinciding with the central axis of the first cylindrical member and a diameter of the second cylindrical member being different from a diameter of the first cylindrical member,

wherein the first antenna and the second antenna are located on a surface of the first cylindrical member,

wherein the third member and the fourth member are located on a surface of the second cylindrical member,

7. The wireless communication system according to claim 1,

wherein the first antenna is located on a surface of the first member,

wherein the second antenna is located on a side of the surface of the first member opposite the first antenna, and

wherein the third antenna is located on the same side of the first member as the first antenna.

8. The wireless communication system according to claim 7,

wherein the first member is a plate-like member, and

wherein the second antenna is located on a surface of the first member opposite to a surface on which the first antenna is located.

9. The wireless communication system according to claim 8,

wherein the movement control unit moves the first member in a predetermined movement direction parallel to a surface of the first member.

10. The wireless communication system according to claim 7,

wherein the movement control unit is configured to rotationally move the first member about a predetermined axis,

wherein the first member is a cylindrical member extending around the predetermined axis serving as a center axis of the first member,

wherein the first antenna is located on an inner surface of the first member,

wherein the second antenna is located on an outer surface of the first member, and

wherein the third antenna is located on a surface of a cylindrical second member, a central axis of the cylindrical second member coincides with a central axis of the first member and a diameter of the cylindrical second member is different from a diameter of the first member.

11. The wireless communication system according to claim 1, further comprising a conductor overlapping the first antenna and the second antenna as seen from a specific direction perpendicular to a plane in which the first antenna and the second antenna are located.

12. The wireless communication system according to claim 11,

13. The wireless communication system according to claim 12,

wherein the movement control unit moves one or more of the first plate-like member and the second plate-like member in a predetermined movement direction parallel to a surface of the first plate-like member and a surface of the second plate-like member.

14. The wireless communication system according to claim 12,

wherein the movement control unit rotationally moves one or more of the first plate-like member and the second plate-like member about a predetermined axis perpendicular to a surface of the first plate-like member and a surface of the second plate-like member.

15. The wireless communication system of claim 12, wherein the conductor is located on a surface of the first plate-like member opposite a surface on which the first and second antennas are located.

16. The wireless communication system of claim 11, wherein the conductor comprises a slit at a position between the first antenna and the second antenna as viewed from the particular direction.

17. The wireless communication system of claim 1, further comprising a conductor configured to act as an electrical ground between the first antenna and the second antenna.

18. The wireless communication system of claim 1, wherein a distance between the first antenna and the third antenna is shorter than a distance between the first antenna and the second antenna.

19. The wireless communication system according to claim 1,

wherein the first communication control unit controls wireless communication by differential transmission of a baseband scheme between the first antenna and the third antenna, and

wherein the second communication control unit controls wireless communication by differential transmission in a baseband scheme between the second antenna and the fourth antenna.

20. The wireless communication system according to claim 1, further comprising a support unit configured to support the first communication device and the second communication device such that the first communication device and the second communication device are movable relative to each other by the movement control unit while maintaining the state.